bicycles = ['trek', 'cannondale', "redline", 'specialized', 12] # 列表[]，无类型数组
print(bicycles)
print(bicycles[0])
print(bicycles[4])
print(bicycles[1].title())
print(bicycles[-1]) # -1是列表最后一个元素，-2是倒数第二个元素，依此类推
print(bicycles[-2])

message = f"My first bicycle was {bicycles[0].title()}."
print(message)